長循環壽命鋰離子電池用鋰金屬上堅固雙相表面層的原位構建
作者:
小柯機器人發布時間:2021/1/3 15:31:06
河南大學趙勇團隊開發了長循環壽命的鋰硫電池用鋰金屬表面堅固雙相表面層的原位構建策略。 相關研究成果發表在2020年12月28日出版的《德國應用化學》。
鋰硫電池作為一種高能量密度的電池系統,具有廣闊的應用前景。然而,鋰多硫化物(LiPSs)的中間體極易穿梭到鋰陽極上,與鋰金屬發生劇烈反應,耗盡活性物質,導致電池快速失效,成為其實際應用的一大障礙。
該文提出了一種簡便的金屬氟化物/二甲基亞碸溶液預處理鋰陽極的方法,用於原位構建堅固的雙相表面層(BSL),它由鋰合金(Li x M)和鋰金屬上的LiF相組成,有效地抑制了穿梭效應,提高了鋰硫電池的循環壽命。具有良好的Li+傳輸能力和力學性能的BSLs不僅能有效地抑制枝晶生長,而且能屏蔽Li陽極與LiPSs的腐蝕反應。採用這種BSLs-Li陽極的鋰硫電池在1 C下的超過1000次循環中表現出優異的循環次數,同時保持98.2%的高庫侖效率。
基於實驗和理論結果,研究人員提出了一種新的基於魯棒BSLs和金屬-硫鍵斥力空間屏蔽的協同機制來抑制穿梭效應,這是實現鋰-硫電池和其他金屬電池系統高穩定性的有效策略。
附:英文原文
Title: In situ Construction of Robust Biphasic Surface Layers on Li Metal for Li‐S Batteries with Long Cycle Life
Author: Wei Guo, Qing Han, Junrong Jiao, Wenhao Wu, Xuebing Zhu, Zhonghui Chen, Yong Zhao
Issue&Volume: 28 December 2020
Abstract: Lithium‐sulfur (Li‐S) battery show application prospect as a high energy density battery system. However, lithium polysulfides (LiPSs) intermediates can easily shuttle to Li anode and severely react with Li metal, which deplete the active materials and cause the rapid failure of batteries, remaining a great barrier for their practical application. Herein, a facile solution‐pretreatment method for Li anodes with metal‐fluorides/dimethylsulfoxide solution is developed to in situ construct robust biphasic surface layers (BSLs), which are consist of lithiophilic alloy (Li x M) and LiF phases on Li metal to efficiently inhibit the shuttle effect and increase the cycle life of Li‐S batteries. The BSLs with good Li + transport ability and mechanical property can not only efficiently inhibit the dendrite growth, but also shield the Li anodes from the corrosion reaction with LiPSs. The Li‐S batteries with such BSLs‐Li anodes show the excellent cycling number over 1000 cycles at 1 C, and simultaneously maintain a high coulombic efficiency of 98.2%. Based on the experimental and theoretical results, we propose a new synergetic mechanism based on the robust BSLs and metal‐S bond repulsion‐space shield for inhibiting the shuttle effect, which is an efficient strategy for achieving high stability Li‐S batteries and other metal battery systems.
DOI: 10.1002/anie.202015049
Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202015049